Varnish.



currno srarns PATENT orrron.

LEO E. muaxiimnn, or YONKEBS, mew roan, AssiqNon. 'ro GENERAL BAKELI'IECOMPANY, OF NEW YORK, N.- Y.,

A CORPORATION OF NEW YORK.

vaniusn.

Specification of war-ram. PatentedFeb. 20,1912.-

' a citizenof the United States, residing at Yonkers, in the county ofWestchester and State of New York, have invented certain new and usefulImprovements in Varnish, of which the following is a s ecification.

. ihisinvention relates to tlie preparation of solutions such. aslacquers or varnishes suitable for application by dipping, brushing,spraying, or other usual methods, and containing as essential componentsa condensation product of phenolic bodies and formaldehyde, and asolvent liquid. The condensation products used are such as are capableof transformation by heat into infusible bodies.

Iti'is now-well understood in the art that phenolic bodies andformaldehfide'are capale' of 'yielding,,according to t e conditions, ofreaction, -a series of differing condensation r'oducts, whereof certainones are solularge excess of phenol in benzol. I

ble' in alcohol, acetone, phenol and some other'liquids but may betransformed by continued heating into insolublebodies. It. has beenroposed heretofore to prepare varnishes rom such initial orpartialconthem in alcohol oracet one, orbydissolvmg an initial condensationproduct contamin' -a ave found that. varnishes so"-pre ared present thedisadvantage of ersistent y retamlnga certain proportion 9 water, whichvery ma ter ally lessens their value 'for certain uses,- particularlysuch as pertain to electrical-m 'Sl1l&tiOIl;' Furthermore, alcoholsabsorb moisture from the. -atmosphere',-fand tendtherefore, particularlyin damp weather, to v 'ield White films andinfer or ,coatings. ree:phenol and cresol alsoret'ainiwat'er ver persistently, even at.comparatively hig temperatures, and *constitutetherefore when present inany considerable propor-I tions. a disturbing element, part cularly whenthe solution is to be'japplied as an electrical insulator." "For:example, an ordi: nary alcoholic solutionof an' inltial conden 'sationproduct of" phenols and formaldehyde contains a cert'ainr ropo'rtion ofwater,- derived both from -t Qudensfation product and from' thecommercial. alcohol f" (as wood alcoholfor instancelieiriploiyed as thesolvent. If the solution contains aisefi'ee phenol or Application filedMarch 14, 1911 Serial No. 614,481.

with a part of the water. By subsequent gentle heating the alcohol ma bepracti- ,cally all eliminated, but a smal proportion of water istenaciously held by the phenol orcresol, In order completely toeliminate this water it is found necessary to continue the heating-untilthe free phenol or cresolis driven off. As long as thephenolic bodyremains it will retain some water, in much the same manner as doessulfuric acid. While uncombined" cresol and a phenol are in this res ectobjectionable constituents of varnis es intended for electricalinsulating purvorable action, imparting to the mass a certain degree ofplasticity or flexibility, and also increasing the solubility of theinitial products, I have foundt-hata varnish 'or solution which avoidsthe foregoing objections while possessing the above-mentioned advantagesand having a very high dielectric stren th may advantageously beprepared as ollows: 7

An initialconden'sation product of phe-- -nols and formaldehyde,prepared for example as described in m I No. 954,666, patented pril 12,1910, using a base as a condensing agent, or by any other I suitable orpreferred method,-is washed or otherwise freed from uncombined phenol,cresol and other foreign matters. The prod not is then freed from waterand dissolved in'any appropriate solvent, as for example acetone oralmixture of acetone and alcohol,

is added in suitable proportion ja materia having 1 a higher" boilm but,having'httleor no am therefore practically inuniscible therewith, saidmater al being also volatile without de composition when-=- -.heated;.at atmospheric are amyl alcohol,-toluene 'and xylene. I proportions of-jth,e ingredients may be ic hp .i for-(3113111918100 P s b weight of;initial condens ation product of. lg ims and formaldehyde, jjsustantl'ally 111117 ,5 spew-bod 1110011 1 to which lia'sebeen'ad edj40arts of acetone-auda- .cresolfit' i's i found that upon drying 'the'parts of commercia alcohol, 'Ighis alcoh'ol is very largely eliminated,together I poses, they-may exert in other ways a fa-Y'; 7

prior U. S.. Patent- To" this v solvent either before or after: thecondensation product is dissolved therein point thanw'ater, ity forWater and 9 'r' 'I-bd fth' h- 1 eter Pressu YP 9 0 1s 0 fllhei -t Widelyvariedxac or ifl t the Practical-16' tquirementslfi varni h suitable formany put: 7

from uncombined phenol. o'rgcresol, dis-j of its higher oiling point,may be retained to an extent sufiicient to impart the desirableplasticity to the mass.- V

Amyl alcohol, in contradistinction to such bodies as glycerin, phenol,cresol, etc., has

little afiinit for water, and this renders it most valua le as anaddition to varnishes for electrical insulating urposes. It may bereplaced by other bo ies possessin the same essential characteristics,viz., a higher boiling point than water and a'lack of ailinity therefor,as evidenced by its immiscibility, the capability of volatilizingwithout decomposition when boiled at atmospheric pressures, togetherwith the property, alone or in conjunction with other solvents,ofyieldin solutions of-the condensation product. T e solvent to be usedwith the amyl alcohol should bereadily volatile, that is to say, itshould have a boilin point not exceeding that of water, and preferablysomewhat lower than this, examples of such solvents being wood alcohol,ethyl alcohol, acetone, andmixtures of these. 1

Varnishes prepared as above may be compounded with certain materialssoluble therein or miscible therewith, as for example resins, oils,including Chinese oil or tung oil, oleo resins and oleo-resinousvarnishes, rubber, gutta percha, asphalt, nitrocellulose and likematerials, which may impart increased elasticity or other desirableproperties to the film. Or the same result .may be secured by increasingthe proportion of amyl alcohol or its equivalents.

In the above specification, as well as in the following claims, the wordphenols is used to designate not only the first member of the phenolicgroup but its homologues,

or phenolic bodies or mixtures thereof,

which are equivalent in this reaction; in

the same way, the polymers of formaldehyde, or other substances whichmay engender formaldehyde, may be used as an equivalent of formaldehyde.

- Theterm varnish as herein used is to be considered as includingbroadly all so lutions of the character described, whether employed asclear varnishes or lacquers, or as vehicles for pigments, inert fillers,etc.

I claim:

1. As a new composition of matter, a varnish comprising a condensationproduct of phenols and formaldehyde substantially free from uncombinedphenols and a solvent therefor, said solvent containin a readilyvolatile organic liquid, and anot er organic 1i uid which is immisciblewith water but miscible with said solvent and of which the boiling pointexceeds that of water.-

2. Es a new composition of matter, a varnish comprising a condensationproduct of phenols and formaldehyde and a' solvent therefor, saidsolvent containing amyl alcohol and a readily volatile organic liquid.

3. As a new composition of matter, a varnish comprising a condensationroduct of phenols and formaldehyde su stantially free fromuncombinedphenols and a solvent therefor, said solvent containing acetone and anorganic liquid of' which the boiling point exceeds that of water.

4. As a new composition of matter, a varnish comprising a condensationproduct of phenols and formaldehyde and a solvent therefor, saidsolevent containing acetone and amyl alcohol.

5. As a new composition of matter, a varphenols and formaldehyde and asolvent therefor, said solvent containing acetone and an organic liquidwhich is 'volatilizable without decomposition when heated at atmosphericpressures, and of which the bo1lin point exceeds that of water.

n testimony whereof, affix my signature in presence of two wltnesses.

.LEO H. BAEKELAND. Witnesses Hnnnnn'r 8. MAY, WM. S. Gonoon, Jr.

